ZHCS114E march 2011 – february 2023 ADS4222 , ADS4225 , ADS4226 , ADS4242 , ADS4245 , ADS4246
PRODUCTION DATA
DC/DC switching power supplies can be used to power DRVDD without issue. It is also possible to power AVDD from a switching regulator. Noise and spurs on the AVDD power supply will affect the SNR and SFDR of th ADC and will show up near DS and as a modulated component around the input frequency. If a switching regulator is used, then it should be designed to have minimal voltage ripple. Supply filtering should be used to limit the amount of spurious noise at the AVDD supply pins. Extra placeholders should be placed on the schematic for additional filtering. Optimization of filtering in the final system will likely be needed to achieve the desired performance. The choice of power supply ultimately depends on the system requirements. For instance, if very low phase noise is required then use of a switching regulator is not recommended.